Why does my computer power supply not have 5 Volts Tags: Power Supplies Computer Systems Last response: December 30, 2010 2:43 PM in Systems Share MSCMOE December 30, 2010 12:33:30 AM Hello, why does my computer power supply show 3 volts and 12 volts but not 5 volts? More about : computer power supply volts jaguarskx a b ) Power supply December 30, 2010 5:02:23 AM don't know and you posted in the wrong section. There should be a 5 volt lead since the hard drive uses both 5v and 12v. Anonymous a b ) Power supply December 30, 2010 8:10:44 AM This topic has been moved from the section Computer Peripherals to section Systems by Fihart Can't find your answer ? Ask ! Get the answer Onus a c 104 ) Power supply December 30, 2010 2:43:37 PM You must be referring to the -5V rail. That rail is obsolete. It was used by some AT expansion cards way back when. Very few PSUs have it any more, and those that do I would not trust to be of sufficient quality to power a modern PC. Can't find your answer ? Ask ! Publish Read discussions in other Systems categories Homebuilt New Build Prebuilt Cases Power Supplies RAM CyberPower !